Channel 4, home to shows like Friends, Ugly Betty and Desperate Housewives, is to buy fewer US dramas in order to spend more money on homegrown shows.
Ugly Betty is one of Channel 4's recent US hits
Outlining its future plans, the channel said it would spend 20% less on imports by 2013 - a drop of around £35m.
It also vowed to plough more cash into factual programmes - showing one new documentary in peak time every day.
The broadcaster, which wants increased public funding, said it aimed to strengthen its public service role.
Channel 4 has already scaled down its reliance on US shows, losing the rights to castaway drama Lost, for example.
Kevin Lygo, the channel's director of television and content, said the cost of such high-profile dramas had risen in recent years, making them an unattractive investment.
"I hope we will continue to source the best US television for our discerning audience," he said.
"But we will reduce both the volume we acquire and the amount we will spend."
The broadcaster also promised to increase its spending on news, and will ringfence £10m a year to be spent on British film.
The channel has also created a new fund to stimulate innovation in digital media - working with games companies and social networking sites like Bebo to bring original content to new audiences.
In addition, it will appoint a commissioning editor with responsibility for multicultural programmes and has promised increased investment in children's and regional programming.
Announcing the changes, Channel 4 chairman Luke Johnson also called on the government to agree new funding for the channel.
He said such a move would give the broadcaster "financial stability" and "preserves its independence from editorial interference".
The broadcaster has predicted a budget deficit of £100m in the next decade as it loses its free analogue broadcasting space following digital switchover.